Universities have an ultimate say in official viva results as they are degree awarding bodies. Programme committee may look at examiners' report and determine that they agree with the examiners and ratify or may overturn the recommendation. Universities have their own regulations on exam which guides examiners when making recommendations. If the committee disagrees with examiners' recommendation, they will normally consult supervisors and internal examiner before making a decision. It is in their interest that candidates are treated fairly and achieve good outcome. On the other hand they have to balance this with respecting externals since they are supposed to be experts in the field and also in the interest of maintaining academic collegiality.

Another thing to consider may be an appeal or complaint if candidates feel strongly that regulations may have been violated or they can demonstrate that the result is not valid. Usually candidates would have supervisor's support to pursue such avenue.

Thirdly, one purpose of vivas is for the thesis and candidate to undergo rigorous academic scrutiny. Examiner's role is the same as that of a peer reviewer. They may reject the research on a number of grounds but where they see academic currency in terms of knowledge contribution, they will make suggestions for improvement or correction. Candidates should therefore be able to expect guidance to help them achieve successful resubmission and re examination.

If the published papers are in highly respected journals, you would rightly feel proud and question the legitimacy of the external's judgement. It may well be that the external are stuck in their own ideology or fall behind knowledge advancement. But these things happen. Beyond the PhD, you will come to learn to deal with such situations where you feel unfairly judgded when youve put so much effort into he work. Some successes are partly associated with whether the person plays the right card at the right time in the right place. Those of us who aren't lucky will feel frustrated. But I would encourage you to stay positive, persevere and maintain your integrity.